Wave solder is melted when the state of its surface oxidation and its relationship with other metal elements (mainly Cu) role in generating a number of residues are inevitable, but proper use of wave soldering equipment, a reasonable and timely clean-up the reduction of tin slag is also essential.

A strict control of furnace temperature

For the Sn63-Pb37 solder are concerned, its normal use temperature of 240-250oC. Use side should always measure the furnace temperature with a thermometer and to assess the uniformity of furnace temperature, namely, the four corners of the furnace and the furnace temperature of the central authorities whether they are consistent, we suggest that bias should be controlled within ¡À 5 oC. Should be pointed out, we can not just look at peak furnace temperature on the instrument display, as a matter of fact instruments show that the temperature and the actual furnace temperature is usually biased. This deviation and equipment manufacturers and equipment are the relationship between use of time.

Second, a high degree of control peak

Peak high degree of control not only for the welding quality is very important in reducing Dross also help. First, the peak should not be too high and should not generally exceed the thickness direction of the printed circuit board 1 / 3, meaning that peak over the top to the printed circuit board soldering surface, but can not exceed component surface. At the same time a high degree of stability of the peak is also very important, depending on the equipment manufacturers. From the principle of speaking, the higher the peak, the surface of solder in contact with the air the greater the oxidation of the more serious, the more tin slag. On the other hand, if the wave instability, the liquid solder when it is easy to fall into the molten solder within the air to accelerate the oxidation of solder.

Third, clean-up

Regularly clean the surface of tin stove is essential. Otherwise, the drop from the peak on the falling tin solder residue on the surface, due to the lack of good heat transfer and enter the semi-solidified state, such a vicious cycle can lead to too much dross.

4, tin added to Article

Every day / every time before booting, you should check the furnace height. Do not open the first wave, but by adding tin to make tin stove inside of solder to achieve the most full. And then open the tin of heating device to melt. Because, the melting of tin will absorb the heat, the furnace temperature is very uneven at this time, it should wait until the tin was totally melted, the furnace temperature reached the state before it can even open peaks. Article tin added in due course help to reduce the welding surface and the height difference between the solder surface, that reduce the peak solder contact area with air can also reduce dross generation.

5, rubbish-like Sn-Cu compounds, the clean-up

In the wave soldering process, the surface of printed circuit boards and electronic components of copper deposited on the copper pins are kept to the molten solder dissolved. The Cu and Sn would form between the Cu6Sn5 intermetallic compound, the compound above the melting point of at 500oC, so it solid form. At the same time, due to the density of the compound 8.28g/cm3, and the Sn63-Pb37 solder density of 8.80g/cm3, so the compound will generally show rubbish like floating on the surface of the liquid solder. Of course, there are some compounds, the leading role due to peak into the solder inside. Therefore, the row of copper work is very important. The methods are as follows: to stop wave, tin furnace heating device normal operation, first tin stove clean up the surface of a variety of residue, exposing the mirror-like state of mercury. Then tin oven temperature down to 190-200oC (At this point solder is still liquid), then stirred with tools such as soldering Tieshao 1-2 minutes (to help solder within the Cu-Sn compounds floating), and then put it aside for 3-5 months hours. As the Cu-Sn compounds, the density of small, put it aside after the Cu-Sn compounds will naturally float on the solder surface, this time you can use tools such as Tieshao to the surface of Cu-Sn compounds, to clean up.

The method can exclude part of the copper. However, if the solder in the copper content is too high, we must consider the Qing furnace. According to production, about every six months or a year to clear furnace once.

6, using anti-oxidant oil

Anti-oxidant oil as a high flash point hydrocarbons, it can float on the surface of the liquid solder, liquid solder and the air will be segregated, thereby reducing the chance solder oxidation, thereby reducing tin slag. In general, the use of anti-oxidant oil can be reduced by about 70% of the tin slag. The specific anti-oxidant oil use, please contact the vendor.